CN100438363C - Bandwidth updating method and control flow for synchronous digital system - Google Patents

Abstract

The present invention relates to a bandwidth upgrading method for a synchronous digital system of digital information transmission and a control flow path thereof, which uses a multiplex section in a synchronous digital system network to protect a circuit single plate in an online upgrading net element. For a loop network, the circuit single plate for protecting is changed and reversed in time when the net element generates the phenomenon that the multiplex section is reversed and protected. For a linear network, after the circuit single plate used for protecting a channel is changed in time, the circuit single plate of a working channel is changed when the multiplex section is reversed and protected. For the linear network, the circuit single plate of the working channel is changed when the multiplex section is reversed and protected, the working channel is recovered, and the circuit single plate used for protecting the channel is changed. After the circuit single plate is changed, the information for the speed rate upgrade of the circuit single plate informs an APS to reverse a protocol. The present invention has the advantages of simple speed rate upgrading operation and less service loss.

Description

A Bandwidth Upgrade Method

technical field

The invention relates to the transmission of digital information, in particular to a bandwidth upgrading method.

Background technique

With the rapid development of IP services, there are more and more demands for bandwidth upgrade of SDH (Synchronous Digital Hierarchy) network, such as upgrading the original STM-16 SDH network to STM-64 SDH network , and because of the small business volume in the early stage of network construction, in order to save investment, telecom operators hope to use low-speed circuit boards such as STM-4 first, and then replace them with higher-speed circuit boards when the business volume increases, etc. It is required that the bandwidth can be upgraded conveniently, and the less impact the upgrade has on the original business, the better.

At present, most SDH devices do not support online upgrade of bandwidth. For example, if an STM-16 ring is completely upgraded to an STM-64 ring, the STM-16 ring will not be retained after the upgrade, and an additional STM-64 ring can only be established first. ring, and then cut over the original STM-16 services to the STM-64 ring, and then remove the original STM-16 ring.

This method of upgrading has two obvious flaws:

1. Creating a new STM-64 ring cannot use the slots used by the original STM-16 ring. If there are no free slot resources available, the upgrade cannot be completed, and the slots used by the STM-16 ring will eventually be used Released, but not available for upgraded STM-64 rings.

2. This upgrade method needs to reconfigure the services of the STM-16 ring on the new STM-64 ring. If the original services are many and complex, the workload of service reconfiguration will be large. In addition, during the service cutover, The damage to the business is also greater.

In a word, the existing upgrade method is complicated to operate and causes great business loss.

Contents of the invention

The object of the present invention is to provide a bandwidth upgrading method and control flow with simple operation and little service loss, so as to overcome the defects of the prior art.

The bandwidth upgrading method adopted in the present invention is as follows: in the synchronous digital system SDH or the synchronous optical network SONET, the line single board in the network element is upgraded online by using the protection of the multiplexing section;

For a ring network, when multiplex section switching protection occurs between network elements, the line board involved in the switching protection is replaced immediately;

The multiplex section switching is generated through forced switching.

After the line single board is replaced, the information about the rate upgrade of the line single board informs the automatic protection switching APS switching protocol;

After the line single board is replaced, the corresponding network element automatically recognizes the rate upgrade, and notifies the automatic protection switching APS switching protocol module of the network element of this information;

After the line single board is replaced, the network management issues a rate upgrade command, and the corresponding network element updates the internal data after receiving the command, and notifies the automatic protection switching APS switching protocol module of the network element of this information.

A bandwidth upgrade method according to the above method, characterized in that: it adopts the following steps:

A1. In a ring network, trigger the multiplex section switching protection of a line segment;

A2. Replace the line single board involved in the switching protection, and inform the automatic protection switching APS switching protocol of the information about the rate upgrade of the line single board;

A3, cancel the multiplex section switching of the line section described in step A1, and restore the working channel;

After the step A3, it may further include the step: A4, repeating the above steps A1-A3, until all line boards in other line sections are replaced and the rate is upgraded.

In the step A1, the line segment triggered by the multiplex section switching protection is embodied as one or more adjacent network element segments;

Another bandwidth upgrading method according to the above-mentioned method is characterized in that: it adopts the following steps:

B1. In a linear network, replace the line board of the protection channel;

B2. Trigger multiplex section switching protection;

B3. Replace the line board of the working channel, and inform the automatic protection switching APS switching protocol of the speed upgrade information of the line board;

B4. Cancel the multiplex section switching and restore the working channel.

Another bandwidth upgrading method according to the above-mentioned method is characterized in that: it adopts the following steps:

C1. In a linear network, trigger multiplex section switching protection;

C2. Replace the line board of the working channel, and inform the automatic protection switching APS switching protocol of the speed upgrade information of the line board;

C3. Cancel the multiplex section switching and restore the working channel;

C4. Replace the protection channel line board.

The beneficial effect of the present invention is that, in the present invention, the multiplex section protection in the synchronous digital system network is used to upgrade the line single board in the network element online. This method does not need to reconfigure the original For some services, obviously, according to the characteristics of multiplex section switching protection, the damage to the service during the upgrade process is small, and the service interruption time is less than 50ms, so that users do not feel that the service has been interrupted, which can be said to be a seamless upgrade, and the present invention directly replaces the original low-rate veneer with a high-rate veneer in the slot where the original low-rate veneer is located, without using other slots, and is easy to operate. Therefore, the present invention The rate upgrade operation is simple and the business loss is small; the invention generates multiplex section switching through forced switching, which helps to improve work reliability, because the priority of forced switching is high, and its switching rate is fast, and the service interruption time is short. Compared with automatic switching, such as pulling out single boards and optical fibers, the switching time of automatic switching needs to add the time for detecting faults on the software. Therefore, during automatic switching, the service interruption time is relatively long, and after automatic switching, if the fault disappears , the software will also automatically recover. When the fault disappears and reappears repeatedly, it will cause switching and recovery to jitter back and forth. When forced switching, it can only be restored by canceling the forced switching, so it is more reliable to use forced switching.

Description of drawings

Figure 1 is a schematic diagram of the comparison of two-fiber bidirectional multiplex section protection switching before and after a fault;

Figure 2 is a schematic diagram of upgrading a two-fiber bidirectional STM-16-level SDH ring to an STM-64-level SDH ring;

Figure 3 is a schematic diagram of 1+1 multiplex section protection in a linear network;

Fig. 4 is a schematic diagram of the basic process of upgrading the ring network;

Fig. 5 is a schematic diagram of the basic flow of linear network upgrade;

FIG. 6 is a schematic diagram of another basic process for upgrading a linear network.

Detailed ways

Below according to accompanying drawing and embodiment the present invention will be described in further detail:

In actual SDH networking, ring network and linear network are commonly used, and complex networks are generally realized by combining and changing these two networking forms. The present invention is aimed at ring network and linear network, Each will be described in detail.

In a ring network, in order to improve network reliability, MSP ring protection is generally configured. Multiplex section ring protection refers to completing a series of protocol handshake processes with the help of K bytes in the multiplex section in the overhead, and performing APS (Automatic Protection Switching, automatic protection switching) switching, so that the service signals originally transmitted on the damaged optical fiber Transfer to the protection channel (generally the opposite direction of the faulty route on the ring) for transmission, so that the original business can continue to be transmitted without interruption.

As shown in Figure 1, four nodes A-B-C-D form an SDH ring. Before a fault occurs, services pass through node B, and nodes A and C go up and down. When these four nodes are configured as multiplex section ring protection, if the route between A and B fails (the most common is a fiber break), the service will be automatically switched to the protection channel in the opposite direction on the ring through the APS protocol , the switching time, that is, the service interruption time, can be less than 50ms.

The present invention utilizes the multiplexing section protection in the synchronous digital system network to upgrade the line single board in the network element online, and when the multiplexing section switching protection occurs between the network elements, the line single board involved in the switching protection is replaced immediately until all line boards are replaced.

The following is an example of upgrading a two-fiber bidirectional STM-16-level SDH ring to an STM-64-level SDH ring. As shown in the SDH ring before the upgrade in the upper part of Figure 2, four network elements 1#, 2#, and 3# , 4# constitute an STM-16-level SDH ring, and the two directions of each network element are STM-16-level line boards. For the convenience of description, the line boards in the two directions of each network element are unified It is planned to be westbound and eastbound line boards, and now it is necessary to replace all STM-16-level line boards with STM-64-level line boards, so as to upgrade the STM-16-level SDH ring to STM-64-level SDH ring, during the upgrade process, the service interruption time is less than 50ms. The specific control process of line board upgrade is as follows:

Step 1: As shown in Figure 2, create a two-fiber bidirectional MSP ring protection. If the STM-16-level SDH ring has already been configured with MSP ring protection, this step can be omitted.

Step 2: Check the status of the full ring to ensure that the MSP ring protection is in the idle state and the ring is normal. Check whether MSP ring protection switching occurs due to a fault. If there is a fault on the ring, remove the fault.

Step 3: As shown in Figure 2 and Figure 4, trigger the multiplex section switching protection of a line segment, for example, allow the multiplex section protection switching to occur between network element 1# and network element 2#, so that the 1# network element The service between the 2# network element is switched to the other direction on the ring. Refer to Figure 1 to prepare for the upgrade of the rate level of the adjacent network element section. Here, the line section that is triggered by the multiplex section switching protection It is represented as an adjacent network element segment.

There are several methods for triggering multiplex section switching, such as automatic switching, manual switching, and forced switching.

Switching triggered by unplugging line boards and optical fibers is automatic switching when a fault occurs, and will automatically resume switching when the fault is eliminated; manual switching and forced switching are triggered by external switching commands issued by users. The priority of manual switching is lower than that of automatic switching. It can only be used when the loop is normal. When the loop fails, it will be replaced by automatic switching. The priority of forced switching is higher than that of automatic switching. In the forced switching state, even if a fault triggering automatic switching occurs on the ring, automatic switching will not be performed, and the forced switching state will remain unchanged.

Send the forced switching command to the east direction of network element #1 or the west direction of network element #2, so that the whole ring is in the forced switching state, and the services on the east direction of network element 1# and the west direction of network element 2# are When switching occurs, the protection channels of network element 3# and network element 4# perform service pass-through, and when the switching is forced, the service interruption time is less than 50ms.

Step 4: As shown in Figure 2 and Figure 4, the line boards involved in the multiplex section switching protection of the above-mentioned line section are the line boards in the east direction of network element 1# and the line board in the west direction of network element #2. Therefore, the network The STM-16 level line boards in the east direction of unit 1# and the west direction of network element 2# were safely removed and replaced with STM-64 level line boards. The two newly inserted STM-64 level line boards Correctly connect STM-64G rate level optical fiber between,

Step 5: As shown in Figure 2 and Figure 4, for single boards of different rate levels, in the multiplex section ring protection, the working channel corresponds to the protection channel is not the same, such as two-fiber bidirectional multiplex section ring protection, STM- The protection channel corresponding to channel 1 of the 16-level line board is channel 9, and the protection channel corresponding to channel 1 of the STM-64-level line board is channel 33, so the upgrade of the rate level of the line board needs to inform the APS switching protocol.

For a plug-and-play system, when NE 1# and NE 2# replace STM-16-level boards with STM-64-level boards, they can automatically recognize the rate upgrade, and the NEs will automatically This information informs the APS switchover protocol module of the network element; for non-plug-and-play systems, there is a difference between logical boards and physical boards. Logical boards are boards created by users, while physical boards are implemented on slots. The inserted board, the configuration on this board is valid only when the logical board is consistent with the physical board, so for this kind of system, after replacing the physical board, the logical board must be changed, the modification of the logical board If user operation is required, the user can directly issue a command to upgrade the speed of the logical board through the network management system. The specific command parameters can include the slot number, the type of the board before the upgrade, and the type of the board after the upgrade. After the command issued by the user, the internal data is automatically updated, and then the information is notified to the APS switching protocol module of the network element.

Step 6: As shown in Figure 2 and Figure 4, issue a command to cancel the forced switching in the east direction to network element 1#, or issue a command to cancel the forced switching in the west direction to network element 2#, so that the multiplex section ring is idle state, the service is restored from the protection channel to the working channel of network element 1# and network element 2#, and when the switching is restored, the service interruption time is less than 50ms.

In this way, as shown in the SDH ring in the middle of Figure 2, the line boards on the east direction of NE 1# and the west direction of NE #2 are changed from hollow circles on the upper part to solid circles, and the corresponding line segments have been upgraded online to STM- 64 levels.

Step 7: As shown in Figure 2 and Figure 4, repeat the operations from Step 3 to Step 6 until all line boards in other line sections are replaced and the rate is upgraded, that is, the rate of each section is upgraded to the STM-64 level , as shown in the SDH ring in the lower part of Figure 2, the rate of the entire SDH ring is upgraded to the STM-64 level.

Step 8: If the upgraded SDH ring does not need to perform multiplex section protection, then delete the multiplex section protection. If multiplex section ring protection is still required, this step can be omitted.

It is worth noting that during the process of repeating steps 3 to 6 in the above step 7, each switching and switching recovery will cause the service on the upgraded section to be interrupted for less than 50ms. If the first network element on the ring This is unavoidable if there are businesses up and down. And if some of the network elements only pass through the services on the ring and do not need to go up and down, the above operations can be simplified to reduce the number of momentary service interruptions. For example, network element 2# only needs to pass through the service on the SDH ring, then when performing step 3, you can issue a forced switching command to the east direction of network element 1# and the west direction of network element 3# at the same time, and switch network element 1# to the west direction at the same time. Between # and NE 2#, and between NE 2# and NE 3#, two adjacent network element sections are upgraded to the STM-64 level, that is, the line section that is triggered by the multiplex section switching protection is reflected as Two adjacent network element segments, in other words, the line boards involved in the switching protection include the east direction of network element 1#, the west direction of network element 2#, the east direction of network element 2# and the east direction of network element 3 The line board in the west direction of # can reduce one switchover and one switchover recovery, so that the impact of service damage is less; similarly, the line section that is triggered by the multiplex section switching protection can also be reflected as more than two adjacent networks meta section.

There are three types of ring network: two-fiber one-way, two-fiber two-way and four-fiber two-way. The operations of different types of multiplex section protection are the same or similar to the online upgrade of bandwidth, which will not be repeated here.

In a linear network, in order to improve reliability, it is generally configured as a linear multiplex section protection. As a type of multiplex section protection, linear multiplex section protection can be divided into 1+1 and 1:N protection modes. As shown in Figure 3, in the 1+1 protection mode, each working system It is protected by a dedicated backup system. In the 1:N protection mode, N systems share one protection system. When the system is normal, the protection system can also be used to transmit additional services, so it can obtain higher protection than the 1+1 system. s efficiency. The linear multiplex section also uses the K1 and K2 bytes in the multiplex section overhead to complete a series of protocol handshake processes to complete APS switching.

The following is an example of upgrading the STM-16-level 1+1 linear multiplex section to the STM-64-level linear multiplex section. As shown in Figure 3, network element A and network element B use the STM-16 level In the 1+1 linear network, network element A and network element B input or output signals from the outside through their respective channel selectors. The specific control process of line board upgrade is as follows:

Step 1: As shown in Figure 3 and Figure 5, when the linear multiplex section is not switched, replace the line board on the slot where the protection channel is located with an STM-16 board with an STM-64 board Line board.

Step 2: As shown in Figure 3 and Figure 5, the information about the rate upgrade of the single board of the protection channel informs the APS switching protocol, and the different processing for the plug-and-play or non-plug-and-play system is the same as that described in step 5 above.

Step 3: As shown in Figure 3 and Figure 5, perform forced switching, and switch the business on the working channel to the upgraded protection channel. During the forced switching, the service interruption time is less than 50ms; similarly, manual switching or automatic switching can be used Switching triggers multiplex section switching.

Step 4: As shown in Figure 3 and Figure 5, replace the line board on the slot where the working channel is located with an STM-16-level line board with an STM-64-level line board.

Step 5: As shown in Figure 3 and Figure 5, the information about the rate upgrade of the single board of the working channel informs the APS switching protocol, and the different processing for the plug-and-play or non-plug-and-play system is the same as that described in step 5 above.

Step 6: As shown in Figure 3 and Figure 5, the forced switching is canceled, and the service is restored from the protection channel to the upgraded working channel. When the switching is restored, the service interruption time is less than 50ms.

For a linear network, the specific control process for another line board upgrade is as follows:

Step I: As shown in Figure 3 and Figure 6, perform forced switching, and switch the business on the working channel to the protection channel. Segment switching occurs.

Step II: As shown in Figure 3 and Figure 6, replace the line board on the slot where the working channel is located with an STM-16 level line board with an STM-64 level line board.

Step III: As shown in Fig. 3 and Fig. 6, the information of the rate upgrade of the single board of the working channel line informs the APS switching protocol, and the different processing for the plug-and-play or non-plug-and-play system is the same as that described in the preceding step five.

Step IV: As shown in Figure 3 and Figure 6, the forced switching is canceled, and the service is restored from the protection channel to the upgraded working channel. When the switching is restored, the service interruption time is less than 50ms.

Step V: As shown in Figure 3 and Figure 6, replace the line board on the slot where the protection channel is located with the STM-16 level single board with the STM-64 level line single board.

Step VI: As shown in FIG. 3 and FIG. 6, the information about the rate upgrade of the single board of the protection channel informs the APS switching protocol, and the different processing for the plug-and-play or non-plug-and-play system is the same as that described in the preceding step five.

To upgrade the bandwidth of a 1:N linear multiplex section, it is similar to upgrading the bandwidth of a 1+1 linear multiplex section. After upgrading the line boards of the protection channels, upgrade the boards where each working channel is located, and details will not be repeated here.

In the online upgrade method of the linear network, the working channel and the protection channel are connected to different line boards.

The above-mentioned methods for online bandwidth upgrade of ring network and linear network have been described in detail. For any SDH network, no matter whether it is complex or not, its topology structure can be expressed as ring network, linear network or two kinds of networks. The simple combination of roads, and the SONET network can also be equivalently replaced according to the above description, therefore, those skilled in the art can complete the online upgrade of any SDH/SONET network bandwidth according to the above description without creative work.

Claims (15)

1. bandwidth upgrading method is applied to it is characterized in that among SDH (Synchronous Digital Hierarchy) SDH or the Synchronous Optical Network SONET:

A1, in ring network, trigger the multiplex section rearrangement protection of a part of path;

A2, the described related circuit veneer of protection of switching of replacing are with the information notification APS APS turning protocol of circuit veneer speed upgrade;

The multiplex section rearrangement of part of path described in A3, the cancellation step A1, the passage of resuming work.

2. bandwidth upgrading method according to claim 1 is characterized in that, also comprises step after the described steps A 3:

A4, repetition above-mentioned steps A1-A3, speed upgrade behind all circuit single-board replacements of other part of path.

3. bandwidth upgrading method according to claim 1 is characterized in that: for ring network, when the multiplex section rearrangement protection took place between the network element, instantaneously changing was switched the related circuit veneer of protection.

4. bandwidth upgrading method according to claim 3 is characterized in that: described multiplex section rearrangement produces by Forced Switch.

5. bandwidth upgrading method according to claim 1 is characterized in that: after described circuit veneer was replaced, corresponding network element is the described speed upgrade of identification automatically, this information was notified the APS APS turning protocol module of this network element.

6. bandwidth upgrading method according to claim 1; it is characterized in that: after described circuit veneer is replaced; issue the order of speed upgrade by webmaster; corresponding network element is received the inner data of this order back renewal, this information is notified the APS APS turning protocol module of this network element.

7. bandwidth upgrading method according to claim 1 is characterized in that: in the described steps A 1, the described part of path that is triggered the multiplex section rearrangement protection is presented as one or more adjacent network element sections.

8. bandwidth upgrading method is applied to it is characterized in that among SDH (Synchronous Digital Hierarchy) SDH or the Synchronous Optical Network SONET:

B1, in linear networking, change protection port line veneer, after the protection circuit veneer was replaced, the message of circuit veneer speed upgrade was informed the APS turning protocol;

B2, the protection of triggering multiplex section rearrangement;

B3, replacing service aisle circuit veneer are with the information notification APS APS turning protocol of circuit veneer speed upgrade;

B4, cancellation multiplex section rearrangement, the passage of resuming work.

9. bandwidth upgrading method according to claim 8 is characterized in that: described multiplex section rearrangement produces by Forced Switch.

10. bandwidth upgrading method according to claim 8 is characterized in that: after described circuit veneer was replaced, corresponding network element is the described speed upgrade of identification automatically, this information was notified the APS APS turning protocol module of this network element.

11. bandwidth upgrading method according to claim 8; it is characterized in that: after described circuit veneer is replaced; issue the order of speed upgrade by webmaster; corresponding network element is received the inner data of this order back renewal, this information is notified the APS APS turning protocol module of this network element.

12. a bandwidth upgrading method is applied to it is characterized in that among SDH (Synchronous Digital Hierarchy) SDH or the Synchronous Optical Network SONET:

C1, in linear networking, trigger the multiplex section rearrangement protection, after the protection circuit veneer was replaced, the message of circuit veneer speed upgrade was informed the APS turning protocol;

C2, replacing service aisle circuit veneer are with the information notification APS APS turning protocol of circuit veneer speed upgrade;

C3, cancellation multiplex section rearrangement, the passage of resuming work;

C4, replacing protection port line veneer.

13. bandwidth upgrading method according to claim 12 is characterized in that: described multiplex section rearrangement produces by Forced Switch.

14. bandwidth upgrading method according to claim 12 is characterized in that: after described circuit veneer was replaced, corresponding network element is the described speed upgrade of identification automatically, this information was notified the APS APS turning protocol module of this network element.

15. bandwidth upgrading method according to claim 12; it is characterized in that: after described circuit veneer is replaced; issue the order of speed upgrade by webmaster; corresponding network element is received the inner data of this order back renewal, this information is notified the APS APS turning protocol module of this network element.

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